e class abs/esp

i just bought a 1999 e200 on wednesday and i just pulled up to my house and the warnings came on for the esp and the abs.anybody got any idea whats gone wrong?or if it will be expensive.

If it was off the next time you started it it was probably a brake light switch.

thanks mate, but it has come on several times since until i restart the engine again-then it will go off.if anyone else has an oppinion i would apprecieate all help!!